ABSTRACT A module M is called strongly FP-injective if Ext i (P, M)= 0 for any finitely
presented module P and all i≥ 1.(Pre) envelopes and (pre) covers by strongly FP-injective …

Let R be a ring and M the left or right R-module category. Let C be a class of R-modules,
closed under extensions, finite direct sums, direct summands and isomorphisms. Suppose …

Several authors have introduced various types of coherent-like rings and proved analogous
results on these rings. It appears that all these relative coherent rings and all the used …

Let R be a ring and M the left or right R-module category. Let C be a class of R-modules,
closed under extensions, finite direct sums, direct summands and isomorphisms. Suppose …

A ring R is called n-coherent if every (n− 1)-presented ideal of R is n-presented. In this
paper, the n-coherence of the perfect closure R∞ is investigated. We show that if R∞ is n …

Let n and d be non-negative integers. We introduce the concept of strongly (n,d)-injective
modules to characterize n-coherent rings. For a right perfect ring R, it is shown that R is right …